Medical filtering devices and methods of use

1. A deployment arrangement comprising a perforated filter device and a delivery catheter therefor, the catheter having a delivery end, and the filter device having an open end and a closed end, the deployment arrangement having a delivery configuration with the open end of the filter device having a shorter distance from the delivery end of the catheter than a distance of the closed end from the delivery end of the catheter, the closed end disposed within the catheter, with the filter device being detached from or releasably attached to the catheter, wherein the deployment arrangement has a deployed configuration, wherein the filter device is everted upon deployment from the delivery end of the catheter such that the open end of the filter is closer to the delivery end of the catheter relative to the closed end and the closed end is disposed outside of the catheter, and wherein the filter device is self-expanding, whereby, after eversion and deployment from the catheter, the open end is detached from the catheter and the filter device including the open end self-expands against the interior walls of a body lumen.

2. An arrangement according to claim 1 , wherein the filter device is configured as a bag.

3. An arrangement according to claim 2 , wherein the material of the bag is braided.

4. An arrangement according to claim 1 , wherein the filter device is of shape memory material.

5. An arrangement according to claim 1 , wherein the filter device is of resilient material.

6. An arrangement according to claim 1 , wherein the open end of the filter device and the delivery end of the catheter are attached by one or more releasable attachment members.

7. An arrangement according to claim 1 , further including a pusher member arranged within the catheter so as to be axially displaceable relative thereto to engage the filter device.

8. A method of deploying a filter device from a delivery catheter into a body lumen, with the filter device being detached from or releasably attached to the catheter, the catheter having a delivery end, and the filter device having an open end and a closed end, comprising the steps of:

inserting the filter device into the delivery catheter with the open end of the filter device being located at a shorter distance from the delivery end of the catheter than a distance of the closed end of the filter device from the delivery end of the catheter;

everting the filter device simultaneously with deploying it from the delivery end of the catheter, and

allowing the filter device, including the open end of the filter device, to expand against the walls of the lumen.

9. A method according to claim 8 , wherein a pusher member is used to evert the filter device.

10. A method according to claim 8 , wherein the step of allowing the filter device to expand against the walls of the lumen is effected gradually during the eversion process.

11. A method according to claim 8 wherein the filter device is substantially fully everted before there is any substantial contact with the walls of the lumen.

12. A method of withdrawing a deployed filter device from a body lumen into a catheter the filter device having an open end and a closed end, comprising the steps of:

moving the catheter inside the lumen toward the filter device from a side of the open end of the filter device with one end of the catheter closer to the open end of the filter device than to the closed end of the filter device;

pulling on the closed end of the filter device from an inside of the filter device, everting the filter device and simultaneously withdrawing the filter device into the catheter; and

removing the catheter from the body lumen with the filter device inside the catheter.

13. A method according to claim 12 , wherein the pulling step is effected by means of a wire permanently attached to the closed end of the filter device.

14. A method according to claim 12 , wherein the pulling step is preceded by the attachment of a wire to the inside of the closed end of the filter device by a connection means, the wire being subsequently used in the pulling step.

15. A method according to claim 12 , wherein the pulling step is preceded by the attachment of a wire to the outside of the closed end of the filter device by a connection means, the wire being subsequently used in the pulling step.